The use of fossil fuel for combustion in an engines requires that the fuel be mixed with air and combustion occur. The combustion process results in rapid oxidation, causing noise, products of carbon monoxide, carbon dioxide, water vapor, smoke and particulates, unburned hydrocarbons, nitrogen oxides and sulfur oxides. In most applications, governmental imposed regulations are restricting the amount of pollutants, including noise, being emitted by the engine.
In the past, attempts to control noise emitted from the engine have included the use of add on shields and insulators. One such example is disclosed in U.S. Pat. No. 4,182,122 issued on Jan. 8, 1980 to Michael K. Stratton et al. With regard to noise emitted from a fuel injector, in many examples the fuel injector is positioned within a cover on the engine as is disclosed in U.S. Pat. No. 3,924,583 issued on Dec. 9, 1975 to Thomas K. Jardin. Thus, the noise emitted from the fuel injector is at least partially dampened by the head cover. However, with the increasing use of unit injectors and the use of higher pressures, split injection and other modes of operation the noise emitted from the fuel injector is, regardless of position within a head cover or open to atmosphere, increasing. With existing fuel injectors, noise created by such fuel injectors fails to be dampened.
Furthermore, as indicated above, present fuel injectors utilize higher injection pressures in an attempt to reduce a portion of the emissions. However, in reducing a portion of the emissions another portion of the emissions, noise is increased. Additionally, more sophisticated control and actuation systems are being used which also tend to increase the noise emitted from the injector. Thus, each of the above contributes to increased noise being emitted from the fuel injector.
The present invention is directed to overcoming one or more of the problems as set forth above.